Paroxysmal nonkinesigenic dyskinesia
Paroxysmal Nonkinesigenic Dyskinesia (PNKD) is an episodic movement disorder first described by Mount and Reback in 1940 under the name "Familial paroxysmal choreoathetosis". It is a rare hereditary disease that affects various muscular and nervous systems in the body, passing to roughly fifty percent of the offspring.